(1) the securitization market for auto ABS is not nearly as dried up as the one for home equity
(2) it's a lot easier to repossess a car than to foreclose on a house
(3) it's a lot easier to sell a repossed car than it is to sell a foreclosed house.

As usual, credit analysis on a bond is a combination of default risk, and recovery expectation.

Quote from bond_trad3r:

They still seem on the low side. Or is it just the fare market rate derived from supply and demand.